1. Field of the Invention
The present invention relates generally to semiconductor devices and, more particularly, to stackable dies using through-wafer vias.
2. Description of the Related Art
Microprocessor-controlled circuits are used in a wide variety of applications. Such applications include personal computers, cellular phones, digital cameras, control systems, and a host of other consumer products. A personal computer, digital camera, or the like, generally includes various components, such as microprocessors, that handle different functions for the system. By combining these components, various consumer products and systems may be designed to meet specific needs. Microprocessors are essentially generic devices that perform specific functions under the control of software programs. These software programs are generally stored in one or more memory devices that are coupled to the microprocessor and/or other peripherals.
Electronic components, such as microprocessors and memory devices, often include numerous integrated circuits manufactured on a semiconductor substrate and coupled together in a package. To increase the density of the circuits, the circuits may be stacked vertically, reducing the ‘footprint” of the circuit. To further reduce the footprint of the circuit and improve electrical connectivity between the dies, the dies may be interconnected by through-wafer vias (e.g. through-silicon vias or TSVs) in which a via passes through the silicon of the dies to provide vertical interconnection. By replacing ribbons, solder wires, or other connection technology typically located on the edge of the dies with TSVs, the length and width of the circuit may be reduced. Additionally, use of TSVs for interconnection may eliminate the need for an interposer between dies. However, because the TSVs must align throughout the stacked dies of the circuit, alignment of the dies during manufacturing may present challenges, especially with respect to small diameter and/or higher density TSVs.